This prediction is a little less plausible than my other one but here it is anyway.

I believe that the bald man holding the gun in the trailer for 400 days, is actualy Vernon. This is because first, why would Vernon leave his group for no reason. Second, i looked at the man and he does look alot like a shaved Vernon (he has small hairs around the same area as Vernon).

This could be wrong but i still felt like posting it.